| 摘要 |
PROBLEM TO BE SOLVED: To provide a diaphragm for a charged particle beam device which can control the temperature of the diaphragm low, and by which vignetting of the charged particle beam incident obliquely is small. SOLUTION: The charged particle beam is made incident from an upper side of the aperture diaphragm 1. The aperture 2 is formed in a multistage shape each stage having a diameter gradually smaller downward. Thereby, in the first place, electrons at a peripheral portion of the charged particle beam are absorbed by the upper surface of the aperture diaphragm 1. Then, the electrons at a more inner portion of the charged particle beam are absorbed by the different area in diameter in the second stage. As similar actions are repeated in order, the beam is gradually absorbed by the multistages. As a result, the aperture diaphragm 1 can be prevented from locally reaching a high temperature. The aperture in the lowest stage works as the actual diaphragm. COPYRIGHT: (C)2005,JPO&NCIPI
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